Dimethyl fumarate, also known by the acronym DMF, is the dimethyl ester of fumaric acid. The compound has a molecular weight of 144.13 daltons and the following chemical structure:
DMF is also known by the names Dimethyl (E)-butenedioate (IUPAC), trans-1,2-Ethylenedicarboxylic acid dimethyl ester and (E)-2-Butenedioic acid dimethyl ester. DMF is typically synthesized by reacting fumaric acid with excess methanol in the presence of an acid catalyst. DMF can also be synthesized according to the methods described in Chinese Patent Publication CN 101318901A.
Fumaderm®, an enteric coated tablet containing a mixture of salts of monoethyl fumarate and dimethyl fumarate was approved in Germany in 1994 for the treatment of psoriasis. Fumaderm® is dosed three times per day with 1-2 grams/day administered for the treatment of psoriasis.
Biogen Idec's BG-12 product, a delayed release (i.e., enteric coated microtablets) oral dosage form of dimethyl fumarate, has been in clinical testing for the treatment of multiple sclerosis. Details concerning the clinical testing of BG-12 are disclosed in Sheikh et al., Safety Tolerability and Pharmacokinetics of BG-12 Administered with and without Aspirin, Key Findings from a Randomized, Double-blind, Placebo-controlled Trial in Healthy Volunteers, Poster PO4.136 presented at the 64th Annual Meeting of the American Academy of Neurology, Apr. 21-28, 2012, New Orleans, La.; Dawson et al., Bioequivalence of BG-12 (Dimethyl Fumarate) Administered as a Single 240 mg Capsule and Two 120 mg Capsules: Findings from a Randomized, Two-period Crossover Study, Poster P913 presented at the 28th Congress of the European Committee for Treatment and Research in Multiple Sclerosis, Oct. 10-13, 2012, Lyon, France; and Woodworth et al., Pharmacokinetics of Oral BG-12 Alone Compared with BG-12 and Interferon β-1a or Glatiramer Acetate Administered Together, Studied in Health Volunteers, Poster PO4.207 presented at the 62nd Annual Meeting of the American Academy of Neurology, Apr. 10-17, 2010, Toronto, Ontario, Canada.
DMF and/or other fumaric acid esters have been proposed for use in treating a wide-variety of diseases and conditions involving immunological, autoimmune, and/or inflammatory processes including psoriasis (Joshi and Strebel, WO 1999/49858; U.S. Pat. No. 6,277,882; Mrowietz and Asadullah, Trends Mol Med 2005, 111(1), 43-48; and Yazdi and Mrowietz, Clinics Dermatology 2008, 26, 522-526); asthma and chronic obstructive pulmonary diseases (Joshi et al., WO 2005/023241 and US 2007/0027076); cardiac insufficiency including left ventricular insufficiency, myocardial infarction and angina pectoris (Joshi et al., WO 2005/023241; Joshi et al., US 2007/0027076); mitochondrial and neurodegenerative diseases such as Parkinson's disease, Alzheimer's disease, Huntington's disease, retinopathia pigmentosa and mitochondrial encephalomyopathy (Joshi and Strebel, WO 2002/055063, US 2006/0205659, U.S. Pat. No. 6,509,376, U.S. Pat. No. 6,858,750, and U.S. Pat. No. 7,157,423); transplantation (Joshi and Strebel, WO 2002/055063, US 2006/0205659, U.S. Pat. No. 6,359,003, U.S. Pat. No. 6,509,376, and U.S. Pat. No. 7,157,423; and Lehmann et al., Arch Dermatol Res 2002, 294, 399-404); autoimmune diseases (Joshi and Strebel, WO 2002/055063, U.S. Pat. No. 6,509,376, U.S. Pat. No. 7,157,423, and US 2006/0205659) including multiple sclerosis (MS) (Joshi and Strebel, WO 1998/52549 and U.S. Pat. No. 6,436,992; Went and Lieberburg, US 2008/0089896; Schimrigk et al., Eur J Neurology 2006, 13, 604-610; and Schilling et al., Clin Experimental Immunology 2006, 145, 101-107); ischemia and reperfusion injury (Joshi et al., US 2007/0027076); AGE-induced genome damage (Heidland, WO 2005/027899); inflammatory bowel diseases such as Crohn's disease and ulcerative colitis; arthritis; and others (Nilsson et al., WO 2006/037342 and Nilsson and Muller, WO 2007/042034).
Pharmaceutical compositions containing DMF and other fumaric acid esters, and/or methods of treatment using same, are disclosed in Joshi et al. U.S. Pat. No. 6,277,882; Joshi et al. U.S. Pat. No. 6,355,676; Joshi et al. U.S. Pat. No. 6,359,003; Joshi et al. U.S. Pat. No. 6,436,992; Joshi et al. U.S. Pat. No. 6,509,376; Joshi et al. U.S. Pat. No. 6,858,750; Joshi et al U.S. Pat. No. 7,320,999; Joshi et al. U.S. Pat. No. 7,612,110; Joshi et al. U.S. Pat. No. 7,619,001; Joshi et al. U.S. Pat. No. 7,803,840; Joshi et al. U.S. Pat. No. 7,915,310; Joshi et al. US 2011/0293711; Joshi et al. US 2011/0124615; Lukashev US 2011/0112196; Nilsson et al. US 2008/0299196; Went et al. US 2008/0089861; Nilsson et al. WO 2007/042034; Nilsson et al. US 2012/0034274; and Nilsson et al. US 2012/0034303.
Many pharmaceutically active agents are susceptible to photodegradation upon exposure to sunlight and/or UV light. Generally, incorporation of light absorbers into formulations can stabilize these photosensitive agents to some extent. For example, N. Jamil et al. (“Studies of the photostability of reserpine in parenteral solutions”, Die Pharmazie, 38: 467-469 (1983)), refers to studies done on the photostability of reserpine in parenteral formulations and the effects of some commonly used stabilizers. U.S. Pat. No. 6,379,697, titled “Stabilization of photosensitive materials” to Gregoriadis, et al. refers to liposomes containing a photosensitive material together with a light absorbing material capable of increasing the photostability of the photosensitive material.
Griffin et al. (“The chemistry of photodimers of maleic and fumaric acid derivatives. I. Dimethyl fumarate dimer”, J Am Chem Soc (1961), 83: 2725-2728), disclose that dimethyl fumarate degrades in the presence of light to form the photodimer compound tetramethyl cyclobutane-1,2,3,4-tetracarboxylate (compound (1)) disclosed herein. See also Griffin et al. U.S. Pat. No. 3,139,395.